海域天然气水合物钻探研究进展及启示:储集层特征*

2015-03-21 05:31乔少华匡增桂梁金强吴能友
新能源进展 2015年5期
关键词:砂质喷口细粒

乔少华,苏 明,杨 睿,匡增桂,梁金强,吴能友†

(1. 中国科学院天然气水合物重点实验室,广州 510640;2. 中国科学院广州天然气水合物研究中心,广州 510640;3. 广州海洋地质调查局,广州 510760)

海域天然气水合物钻探研究进展及启示:储集层特征*

乔少华1,2,苏 明1, 2,杨 睿1,2,匡增桂3,梁金强3,吴能友1,2†

(1. 中国科学院天然气水合物重点实验室,广州 510640;2. 中国科学院广州天然气水合物研究中心,广州 510640;3. 广州海洋地质调查局,广州 510760)

本文基于世界范围内天然气水合物勘探的研究成果,系统回顾和总结了含水合物的沉积体类型,即水合物的储集体。根据水合物的实际分布和产出特征,将水合物藏划分为非渗透的细粒泥质沉积物中浸染状水合物、含裂隙的细粒泥质沉积物中裂缝充填型水合物或结核结壳型水合物、流体喷口附近海底浅表层水合物、粗粒砂质沉积物中孔隙充填型水合物四类。其中细粒沉积物孔隙度较小,渗透率较低,水合物饱和度低,开采难度大;流体喷口附近浅表层水合物分布范围十分局限,开采风险大;裂缝充填型水合物的分布主要受活动断层或微裂隙的控制,其形成机制和原位资源量仍不清楚;粗粒沉积物孔隙度较大、渗透率较高、水合物以高饱和度的孔隙充填型为主,矿体展布集中、开采难度较小。根据水合物原位资源量和开采难度,它们分别自下而上位于水合物资源金字塔的底部到顶部。以水合物油气系统思想为指导,寻找砂体中的水合物藏是现在和将来水合物勘探的重要方向之一。

天然气水合物;水合物资源金字塔;储层特征;砂体;水合物开采

0 前 言

技术的发展使得原先无法被开采的非常规天然气资源展现了新的曙光,如深水油气(水深超过300 m)、煤层气和页岩气等。近年来的数值模拟[1-2]和开采试验[3-4]表明,天然气水合物同样可以提供具有经济价值的天然气资源。水合物矿体展布的确定和产气速率的提升是水合物的开采利用需要解决的两个关键问题[5]。在水合物油气系统中,合适的储层是水合物富集成藏的关键因素之一[6]。因此,对水合物开采利用而言,针对水合物储层的研究显得十分重要。

大洋钻探计划(Ocean Drilling Program, ODP)和综合大洋钻探计划(Integrated Ocean Drilling Program, IODP)以水合物为目标的不同航次(如ODP 164航次和204航次、IDOP311航次等),以及各个国家开展的水合物专项研究计划(如墨西哥湾联合工业计划JIP、日本南海海槽水合物计划、印度国家水合物计划NPGH和韩国郁龙盆地水合物计划UBGH等),获取了相当可观的地质资料,并针对水合物的储层进行了大量研究。这些钻探研究结果表明,水合物的储层类型及产出特征主要可以分为粘土质沉积物中低饱和度浸染状充填型水合物[7]、流体喷口附近暴露于海底的块状水合物[8]、含裂隙的粘土质沉积物中裂缝充填型水合物[9-10]、以及砂质沉积物中孔隙充填型水合物[11-12]。不同类型的储层中水合物的产出特征有着明显差异。因此,系统地总结和归纳全球范围内水合物富集区的储层特征,有利于我们对水合物成藏机制的理解和认识。

1 水合物资源金字塔

由于缺少实际资料,二十世纪八十年代人们认为在相对稳定的温度和压力环境下,海底水合物稳定带内的水合物可能是普遍存在的[13]。现在人们发现,由于横向和纵向上孔隙水盐度和热流等因素的变化,水合物稳定带有着十分复杂的几何形态。进一步来讲,稳定带内水合物的产出既非连续也非随机,而是受控于水合物系统要素(温度、压力等)和含油气系统要素(包括气源、运移通道和储集空间等),即水合物含油气系统[6]。不同地质背景下的水合物有着完全不同的分布范围和产出特征,为了更好地指导水合物的勘探和开采,BOSWELL等[14]提出了“水合物资源金字塔”(the Gas Hydrates Resource Pyramid)模型。

水合物资源金字塔(图1)显示了各种类型水合物资源的相对规模和开采难度,最具资源潜力的水合物类型位于金字塔顶端,开采难度最大的水合物类型位于金字塔底部。从上至下,分别为砂质沉积物中的水合物、含裂隙沉积物中的水合物、喷口附近的水合物,以及粘土质沉积物中的水合物。水合物资源金字塔表明,尽管粘土质沉积物中的水合物具有最大的原位天然气资源量,但是由于其较低的渗透率而极具开采难度;而含水合物的砂质沉积物具有较好的孔渗性,且水合物多以孔隙充填的形式产出,富集程度高(饱和度高),因此最具开采潜力[16]。为了更好地研究水合物的富集成藏规律,以及为将来的生产开采服务,从水合物储层特征的角度来研究水合物显得十分必要。

图1 水合物资源金字塔(修改自[14-15])Fig. 1 The gas hydrate resource pyramid (modified from reference [14-15])

2 细粒沉积物中的水合物

远离陆地的深水背景下,海洋沉积物中通常缺少砂质(粒径为0.062 5~2 mm),主要以粘土(粒径<0.004 mm)和粉砂(粒径为0.004~0.062 5 mm)为主。海洋细粒沉积物(半远洋沉积物)的渗透率随着深度的增加呈指数下降,从海底附近的10−12m2可迅速降低至140 mbsf的10−17m2左右[17]。一般认为极低渗透率的细粒沉积物中流体以扩散方式运移为主,而对流作用并不明显[18]。在以扩散方式为主的水合物体系中,水合物具有“厚度小、饱和度低”的特点[19]。但由于随着沉积物的堆积而产生的水合物分解再循环,稳定带底界附近的水合物饱和度往往较高[20]。

细粒沉积物中的水合物以布莱克海台最为典型。覆盖于布莱克海台的底流沉积物物性非常均一,主要为富超微化石的黏土,以及含量不等的蛋白石,粒径小于0.001 mm的沉积物颗粒含量超过70%[22-23]。大部分水合物以低饱和度(<10%)的浸染状产出,基本不影响沉积物的结构(图2a)。水合物分解造成了孔隙水盐度异常低值区,而这些低值区通常对应着硅质微体化石富集的层位[22]和沉积物颗粒相对较大的层位[23],这表明了岩性对水合物分布的控制作用。另一方面,有微裂隙或者断层经过的层位中有直径为cm级的块状或脉状水合物的产出(图2b和图2c),这说明流体运移通道可以造成水合物的局部富集[24]。

图2 细粒沉积物中典型的水合物产出特征:(a)浸染状水合物,又称弥散状水合物,通常肉眼不可见,但可以通过红外热成像仪观察到明显的低温异常,水合物分解后,沉积物可呈现汤状或奶油状;(b)脉状充填型水合物[21];(c)块状水合物[7];脉状和块状水合物一般发育在细粒沉积物中有断层或者裂隙切穿的地方Fig. 2 Occurrences of hydrates in fine grained sediments: (a) disseminated hydrate, which is invisible to the naked eye, but can be detected by infrared thermal imager, mouss-like sediment surface possibly indicated degassing or hydrate decomposition; (b) vein filling hydrate; (c) massive hydrate; vein filling hydrates and massive hydrates occur in the intersection of faults or micro fractures in fine grain sediments

细粒沉积物中的水合物藏类似于MILKOVEE等[25]提出的“地层圈闭水合物藏”,世界上大部分水合物可能赋存于这种类型的储集体中。细粒泥质沉积物拥有较小的孔隙空间和较大的毛细压力,不利于甲烷的运移和水合物的成核[26],因此水合物通常以低饱和度的浸染状产出,偶尔以块状形式出现。尽管细粒沉积物中水合物的原位储量巨大,但现有的开采工艺并不能对该类型的水合物藏进行经济而有效的开发利用。

3 含裂隙带中的水合物

如果细粒富泥沉积物发育一些裂隙,也可以被认为具有一定的可渗透性,水合物可充填于这些裂隙之中,形成裂缝充填型水合物藏。cm级的结核、结壳型水合物可以看作是一种特殊的裂缝充填型水合物。相比细粒沉积物中浸染状的水合物,含裂隙带中的水合物通常肉眼可见(图3b和图3c)。RUPPEL等[27]认为裂隙的存在增大了沉积物的次级孔隙度和渗透率,并促进了汇聚型流体流动的形成,有利于水合物的形成。COOK等[28]认为,当孔隙水中甲烷浓度超过其溶解度时,水合物会沿着沉积物的破裂面充填于孔隙之中。沉积物沿着平行于最大主应力的方向(竖直方向)破裂,因此水合物通常呈直立充填状(图3e)。

世界范围内近年来的水合物勘探研究表明,裂缝充填型水合物比之前估计的更常见,如水合物脊[29]、卡斯卡迪亚大陆边缘[30]、印度K-G盆地[9],以及韩国郁龙盆地等[31]。除此之外,断裂带的砂体中也有可能存在规模不等的裂隙。例如断层十分发育的墨西哥湾Green Canyon 955站位附近,裂缝充填型的水合物被列为一个重要的勘探目标[32-33]。

气烟囱构造是郁龙盆地最主要的流体运移通道之一,水合物充填于气烟囱的裂隙之中[34]。流体的快速充注会加速水合物的形成,进而在浅层形成“水合物帽”,在海底形成地形高地(图3a)[35]。除裂缝充填型外,气烟囱内部还有大量结核结壳型水合物。与郁龙盆地小型裂隙不同,K-G盆地NGHP-01 -10站位揭示的水合物藏与大型的断层体系密切相关。NGHP-01-10站位位于一组近南北向的断裂和一组NE向的断裂交汇处的向北一侧(图3d)。构造变形使甲烷气体能够沿着沉积物变形、断层和倾斜层向上运移至海底,砂质沉积物的缺乏使得水合物趋于富集于岩层的裂缝之中[36](图3e和图3f)。在众多断裂的相互影响下,多边形断层在该地区也十分发育,进一步扩大了裂缝充填型水合物的分布范围。

如果裂隙是由水合物或者游离气的超压造成,水合物的分布范围将会十分局限,如郁龙盆地气烟囱;构造活动形成的断裂是区域性的,水合物有可能大面积赋存,如K-G盆地NGHP-01-10站位附近。前者的资源潜力有限,而后者可能具有较高的开采经济价值。因此,对裂隙充填型的水合物藏而言,裂缝形成机制和水合物聚集机制的研究将十分重要。

图3 裂缝充填型水合物典型的产出背景和产出特征:(a)郁龙盆地气烟囱及其内部空白反射特征;(b)气烟囱内部低角度裂缝充填型水合物的X射线计算机断层扫描图;(c)气烟囱内部裂缝充填型水合物实物样品;(d)K-G盆地NGHP-01-10站位附近两组断裂交汇处地震属性(振幅)时间切片;(e)断层交汇处钻探样品的三维X射线计算机断层扫描图(白色为水合物,蓝色为冰);(f)NGHP-01-10站位裂缝充填型水合物实物样品Fig. 3 Occurrences of fracture filling hydrates: (a) gas chimney and the blank zone in the Ulleung basin; (b) X-ray CT image of low angle fracture filling hydrate; (c) fracture-filling hydrate sample in gas chimney; (d) time slice of seismic attribute (amplitude) nearby the site NGHP-01-10 in the K-G basin; (e) 3-D X-ray CT images in the intersection of fault with hydrate highlighted in white and ice in blue; (f) fracture-filling hydrate sample in site NGHP-01-10

4 流体喷口附近的水合物

流体喷口中气体以微气泡或溶解相运移,喷溢特征常具间歇性。喷口可能有一个流体运移中心通道,或者竖直的多孔高渗透区域。海水/海底界面附近的快速冷却作用使得水合物在海底表面沉积物中形成(图4c)。流体喷口附近水合物通常与深部的裂缝充填型水合物系统相连通,这些裂缝最初可能是流体朝海底快速喷溢的通道,墨西哥湾GC955站位的重要目标之一就是寻找下伏的裂缝充填型水合物[33]。此外,它们的出现通常伴随着暴露于海底的丘状体、碳酸盐岩硬地、麻坑、泥火山以及化学合成生物群落等(图4b)[37-39]。早期的墨西哥湾水合物研究中正是以这种浅表层水合物为研究重点[40-41]。

目前针对流体喷口的研究多集中在生物地球化学及其生态环境效应方面,浅表层水合物形成机制仍不清楚。PECHER等[45]认为水合物稳定带之下的游离气有可能沿着由水合物包裹的通道运移至浅表层,由于没有足够的自由水,气相的甲烷并不会在运移过程中结晶形成水合物。HO等[46]指出,以水为主要成分的流体喷口含有一定的热量,会加热喷口附近的沉积物,进而导致稳定带的减薄,形成局部的穹窿状BSR(图4a)。然而,研究人员利用电导温度深度传感器和测温探针获取了新西兰外海Hikurangi大陆边缘的实际数据,测试结果并不支持上述认识[47]。这表明流体喷口附近浅表层水合物的形成机制可能远比预想中的复杂。

流体喷口附近的水合物以其埋藏浅的特点,早期的水合物研究中实物样品的钻获相对容易。然而,以油井为主的常规油气开采技术无法有效地开采这类水合物藏。此外,由于海底表层生态系统的敏感性,其他开采技术也十分受限。因此,流体喷口附近浅表层水合物藏的经济价值十分有限。

图4 流体喷口附近相关的地质特征:(a)墨西哥湾典型流体喷口地震剖面特征,可见突起于海底的丘状体,同相轴有上拉特征[42];(b)日本Joetsu盆地水合物丘状体多波束地形特征,丘状体内部发育一个可能因水合物分解而形成的负地形(麻坑)[43];(c)墨西哥湾Bush海山附近表层水合物实物(水深541 m),水合物分解产生了大量甲烷气泡[44]Fig. 4 Geologic feature nearby the fluid venting: (a) seismic section crossing a venting in the GOM; a mound in seafloor and pull-up of events can be seen; (b) multibeam bathymetric map hydrate mound in the Joetsu basin, Japan; a pockmark can be seen in the mound; (c) massive hydrate exposed to the seafloor in the Bush hill, the GOM (water depth=541 m); methane bubbles escape when hydrates decompose

5 砂体中的水合物

水合物更趋于聚集在细粒沉积物的粗粒夹层中,是最常见的岩性对水合物分布控制的表现[23,48]。相对于细粒沉积物,粗粒沉积物有着更大的孔隙度、渗透率,更适合水合物的富集。日本南海海槽的实际钻探资料表明,含水合物的砂质沉积物孔隙度可达55%,而泥质沉积物的孔隙度大多小于40%[49]。较大的孔隙空间拥有较小的毛细压力,使得水合物可以以较高的饱和度聚集,如南海海槽PSW-1井和Mallik 5L-38井砂层中水合物的饱和度最高可达80%(图5a)[50]。此外,含水合物的砂体横向渗透率在0.00~0.1 md之间,而饱和水的砂体渗透率可在100~1 000 md之间[3]。因此,砂体是海域水合物最理想的储集空间,位于水合物资源金字塔顶部。

2000年日本MITI南海海槽钻井最早揭示了水合物在泥砂交互的沉积物中的分布特征。这个钻井钻遇的沉积物由厚度不等的细砂至中砂和粉砂/粘土互层组成(图5b)。其中砂层厚度一般小于1 m,是浊积相中半深海未固结沉积物[51]。水合物富集在碎屑砂质沉积物中,饱和度最高为80%,总厚度达12~14 m(图5c)。南海海槽进一步的研究计划(Tokai-oki至Kumano-nada计划)中,浊积砂体成为了勘探的重点目标,并取得了预期的结果[11]。

自此以后,根据水合物油气系统的思想寻找砂体中的水合物成为了水合物勘探研究的重要任务之一,例如墨西哥湾JIP II航次、印度大陆边缘NPGH01航次和韩国UBGH02航次。JIP II航次自西向东分别在墨西哥湾Alaminos Canyon 21区块、Walker Ridge 313区块和Green Canyon 955区块设置了若干站位,以研究块体搬运沉积(Mass Transport Deposits, MTD)、盆底扇、浊积水道−天然堤复合体系,以及远端扇等环境中砂体对水合物的控制作用(图6)[12]。JIP II航次钻探结果揭示,砂层对水合物的分布起到了很好的控制作用,水合物可以在远离稳定带底界的砂层中聚集,饱和度达50%~90%[55]。

图5 日本南海海槽以砂体为目标的水合物站位地震剖面、岩芯和含水合物的砂质沉积物实物样品:(a)设定该站位的依据主要包括明显的BSR、BSR之上的强反射及高速异常体、水道特征以及浊流沉积体[52];(b)南海海槽某保压取芯的X射线CT扫描图,粘土层、粉砂层和砂层清晰可见[53];(c)南海海槽某保压取芯中含水合物的砂质沉积物实物样品,水合物以孔隙充填的形式赋存于砂质沉积物的孔隙空间中[54]Fig. 5 Core, hydrate-bearing sand-dominated sediments sample, and seismic profiles crossing hydrate sites in the Nankai trough: (a) existence of BSR, strong seismic reflectors above BSR, relatively higher interval velocity and turbidite sequence are the four requirements for the hydrate sites[52]; (b) X-ray CT image of pressure core in the Nankai trough; clay layer, silt layer and sand layer can be distinguished clearly[53];(c) hydrate-bearing sand-dominated sediment sample in the Nankai trough, hydrate occur in the porespace in the sediments

图6 墨西哥湾JIP II航次以各类砂体为目标的站位:(a) AC21站位的目标砂体为富砂MTD[12];(b)和(c)GC955站位和WR 313站位的目标砂体为水道−天然堤复合体系中天然堤砂体,WR313站位含蓝色层、橘色层和绿色层三套砂层[12,55]Fig. 6 Hydrate sites aiming at sand layers in JIP II leg in the GOM: (a) the target sand layer of site AC21 is sand-rich MTD; (b) and (c) the target sand layers of site GC955 and WR313 are channel-levee complex sand bodies; there are three sand layers in site WR313, which are yellow unit, orange unit and green unit[12,55]

印度大陆边缘NGHP-01-15站位设置在了水道−天然堤复合体系之上,钻遇了5~8 m厚的砂层(图7a和图7b)。这些砂质沉积物可能是深部的水道充填或天然堤沉积物,其中水合物饱和度为20%~40%。韩国UBGH02航次大部分站位都以富砂浊积物为施钻目标。18个钻井的钻探结果显示,水合物主要有两种赋存形式:①砂质沉积物中的孔隙充填型水合物;②泥质沉积物中的裂缝充填型和结核结壳型、浸染状水合物[31]。砂层中的水合物饱和度与砂质含量呈正相关,泥质沉积物中这样的关系并不明显(图7d)[56]。UBGH02航次的钻探结果表明,盆地范围内大范围分布砂质浊流沉积体是郁龙盆地水合物最重要的储集体。

如前所述,海洋沉积物中相对粗粒的砂层对水合物的分布起到了很好的控制作用。砂层中孔隙度较大、水合物饱和度高,水合物分解后沉积物渗透率较大,因此砂质储集体中的水合物藏是最理想的勘探和开采目标。然而由于水合物赋存的远洋深海背景,浅层的砂体并不常见,高昂的深水勘探费用是这类水合物藏需要面对的挑战之一。

图7 以浊积砂体为目标的印度大陆边缘NGHP-01-15站位和韩国郁龙盆地UBGH02-6站位:(a)NGHP-01-15站位设置在水道东侧的天然堤之上,砂体出现深度为80 mbsf左右;(b)80 mbsf处的砂层特征[57];(c)UBGH02-6站位的目标层位是浅部半远洋沉积层中的浊积砂层,该层沉积物是一套透镜状的碎屑流沉积[58];(d)沉积物中水合物的饱和度与砂质颗粒含量呈明显的正相关[31]Fig. 7 Site NGHP-01-15 and site UBGH02-6 aiming at turbidite sands in the margin of India and the Ulleung Basin: (a) site NGHP-01-15 is located on the levee of channel, and the sand layer occure in the depth of 80 mbsf; (b) sand layer in 80 mbsf[57]; (c) the target layer of UBGH02-6 is the turbidite sand section in the shallow hemipelagic sediments, which is composed of lenticular debris depositions[58]; (d) a nearly linear increase in gas hydrate saturation with increasing sand content in sandy sediment; whereras gas hydrate saturations within muddy sediments was independent of sand content[31]

6 结论与讨论

根据水合物的产出特征可以将其分为细粒沉积物中的水合物、含裂隙带中的水合物、流体喷口附近的水合物、砂体中的水合物四类。细粒沉积物中浸染状水合物的原位储量巨大,但水合物饱和度较低、沉积物渗透性较差;流体喷口附近的水合物分布范围十分局限。与构造活动(断层)相关的裂缝充填型水合物藏分布面积常具区域性。综合考虑开采工艺难度和生态环境效应,这三类水合物藏的开采经济价值不高。

浅层海洋砂体具有较高的孔隙度和渗透率,是水合物最好的储集体类型,水合物可以以高饱和度的孔隙充填形式赋存。砂体中的水合物藏具有最低的开采难度和最优的开采潜力,常规的油气开采设备可适用于砂质储集体中的水合物藏,因此砂质储集体是最具有经济价值的水合物开采目标,位于水合物资源金字塔顶部。因此,根据水合物油气系统的思想,寻找这些富砂背景下的水合物藏是现在和未来水合物勘探的重要任务之一。

水合物所赋存的沉积体具有埋深浅、年代新、沉积环境复杂等特点。针对水合物的研究往往多集中在浅层沉积体,这需要综合利用高精度二维/三维地震资料、浅剖资料和多波束海底地形资料。此外,深海环境中沿陆坡倾向的重力作用与沿陆坡走向的等深流作用常相互影响,深海悬浮沉积、重力流沉积物再搬运及再沉积作用经常发生,形成具有复杂成因的地形和构造,进一步影响水合物的分布。加强对浅层深水沉积体沉积学的研究,是我们进一步认识和掌握水合物成藏机制的重要途径。

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The Progress and Revelations of Marine Gas Hydrate Explorations: Reservoir Characteristics

QIAO Shao-hua1,2, SU Ming1,2, YANG Rui1,2, KUANG Zeng-gui3, LIANG Jin-qiang3, WU Neng-you1,2
(1. Key Laboratory of Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China;2. Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China;3. Guangzhou Marine Geological Survey, Guangzhou 510760, China)

The types of gas hydrate-bearing sediments were reviewed and summarized systematically based on the worldwide hydrate exploration results. Four different gas hydrate types or occurrences are known: (1) low-concentration, disseminated hydrate in mostly impermeable clays, (2) fracture filling hydrate in clay-dominated fractured sediments, (3) massive hydrate exposed on the seafloor around the venting, and (4) pore-filling hydrate in sand-dominated sediments. Fine grained muds and shales have low porosity, low permeability and low hydrate saturation, the prospects for economic recovery of natural gas from this highly disseminated hydrate are very poor with current technologies. Commercial recovery of hydrate from ventings is unlikely because of economic and technology hurdles and the probable destruction of sensitive sea-floor ecosystems. The distribution of fracture-filling hydrates is controlled by active faults and micro fractures, and the formation mechanism and in-place resources of this type of hydrate accumulation are still unknown. Coarse grained sediments have large porosity, high permeability, and the pore-filling hydrate have high saturation, which means sand reservoirs are conducive to existing well-based production technologies. These four types of hydrate accumulations are located in the resource pyramid from the bottom to the top. Search for hydrate in sand-dominated reservoirs using hydrate petroleum system as guiding ideology is one of the most important researching directions for hydrate exploration in the future.

gas hydrate; gas hydrate resource pyramid; reservoir characteristics; sand-dominated reservoir; hydrate production

TK01;TE1;P736

A

10.3969/j.issn.2095-560X.2015.05.007

2095-560X(2015)05-0357-10

2015-01-16

2015-08-28

国家自然科学青年基金项目(41202080);中国石油科技创新基金研究项目(2013D-5006-0105);油气藏地质及开发工程国家重点实验室(成都理工大学)开放基金项目(PLC201407);中国科学院重点部署项目(KGZD-EW-301)

† 通信作者:吴能友,E-mail:wuny@ms.giec.ac.cn

乔少华(1988-),博士研究生,从事天然气水合物成藏地质条件分析等方面的科研工作。

吴能友(1965-),研究员,博士生导师,主要从事海洋天然气水合物成藏机制和资源评价、海洋石油天然气资源评价等方面的科研工作。

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